Effect of an Intensive Nurse Home Visiting Program on Adverse Birth Outcomes in a Medicaid-Eligible Population: A Randomized Clinical Trial

Abstract

Importance: Improving birth outcomes for low-income mothers is a public health priority. Intensive nurse home visiting has been proposed as an intervention to improve these outcomes.

Objective: To determine the effect of an intensive nurse home visiting program on a composite outcome of preterm birth, low birth weight, small for gestational age, or perinatal mortality.

Design, setting, and participants: This was a randomized clinical trial that included 5670 Medicaid-eligible, nulliparous pregnant individuals at less than 28 weeks' gestation, enrolled between April 1, 2016, and March 17, 2020, with follow-up through February 2021.

Interventions: Participants were randomized 2:1 to Nurse Family Partnership program (n = 3806) or control (n = 1864). The program is an established model of nurse home visiting; regular visits begin prenatally and continue through 2 postnatal years. Nurses provide education, assessments, and goal-setting related to prenatal health, child health and development, and maternal life course. The control group received usual care services and a list of community resources. Neither staff nor participants were blinded to intervention group.

Main outcomes and measures: There were 3 primary outcomes. This article reports on a composite of adverse birth outcomes: preterm birth, low birth weight, small for gestational age, or perinatal mortality based on vital records, Medicaid claims, and hospital discharge records through February 2021. The other primary outcomes of interbirth intervals of less than 21 months and major injury or concern for abuse or neglect in the child's first 24 months have not yet completed measurement. There were 54 secondary outcomes; those related to maternal and newborn health that have completed measurement included all elements of the composite plus birth weight, gestational length, large for gestational age, extremely preterm, very low birth weight, overnight neonatal intensive care unit admission, severe maternal morbidity, and cesarean delivery.

Results: Among 5670 participants enrolled, 4966 (3319 intervention; 1647 control) were analyzed for the primary maternal and neonatal health outcome (median age, 21 years [1.2% non-Hispanic Asian, Indigenous, or Native Hawaiian and Pacific Islander; 5.7% Hispanic; 55.2% non-Hispanic Black; 34.8% non-Hispanic White; and 3.0% more than 1 race reported [non-Hispanic]). The incidence of the composite adverse birth outcome was 26.9% in the intervention group and 26.1% in the control group (adjusted between-group difference, 0.5% [95% CI, -2.1% to 3.1%]). Outcomes for the intervention group were not significantly better for any of the maternal and newborn health primary or secondary outcomes in the overall sample or in either of the prespecified subgroups.

Conclusions and relevance: In this South Carolina-based trial of Medicaid-eligible pregnant individuals, assignment to participate in an intensive nurse home visiting program did not significantly reduce the incidence of a composite of adverse birth outcomes. Evaluation of the overall effectiveness of this program is incomplete, pending assessment of early childhood and birth spacing outcomes.

Trial registration: ClinicalTrials.gov Identifier: NCT03360539.

Figure 1.. Screening, Randomization, and Analysis Flowchart

^aThe reasons participants were deemed ineligible were not systematically documented and so cannot be reported. ^bRandomized in a 2:1 ratio to receive program services (intervention) or control, without stratification. ^cParticipation in the program was not recorded for participants who withdrew from the study. ^dParticipant may have received intervention services. Participant matched to a record in the Maternal, Infant, and Early Childhood Home Visiting program, indicating participation in the intervention program, but did not match to internal program records. ^eProbable pregnancy loss was defined as having a diagnosis code for spontaneous abortion, ectopic pregnancy, or molar pregnancy in hospital discharge records or Medicaid claims within the expected delivery date and 42 weeks prior (eMethods in Supplement 2, section 5). ^fIndex pregnancy was defined as having at least 1 of the following: an index birth or fetal death, an indication of delivery in hospital discharge records or Medicaid claims within 120 days of the expected delivery date, a probable pregnancy loss in hospital discharge records or Medicaid claims, an antenatal care visit in Medicaid claims, or enrollment in Medicaid within the expected delivery date and 42 weeks prior. ^gIndex births were defined as matched births that appear in South Carolina vital records birth certificates within 120 days of the expected delivery date of the participant reported on the baseline survey.

Figure 2.. Effect Heterogeneity

Estimated coefficient and its 95% CI from adjusted regression model for 3 analytical groups: whole sample (N = 4966), vulnerable subgroup (n = 2304), and non-Hispanic Black subgroup (n = 2565). The vulnerable subgroup comprises those who were younger than 19 years, had not finished high school, or had challenges with mental health (Patient Health Questionnaire 2 score ≥3 at baseline or reported receiving mental health treatment in the year before enrollment). Because of persistent racial disparities in birth outcomes, program outcomes were analyzed among participants who self-identified as non-Hispanic Black. Secondary outcomes here were chosen as illustrative. See eTable 7 and eFigure 7 in Supplement 2 for subgroup analysis for all maternal and neonatal health-related secondary outcomes. Registered primary outcomes include composite adverse birth outcome, interbirth intervals less than 21 months, and composite of major injury or indicators of abuse or neglect in the child’s first 24 months. The first primary outcome is reported here; the other 2 primary outcomes will be reported in subsequent publications when data are fully available (July 2023). ^aPercentages are shown for binary outcomes. ^bThe difference between the usual care group mean and the nurse home visiting group mean may not equal the unadjusted difference column because of rounding. ^cAdjusted regression models included baseline covariates for implementing agency, demographics (age, education, race and ethnicity), gestational length, relationship with father of the child, employment, housing stability and indicators of physical and mental health. See eMethods in Supplement 2, sections 4 and 6, for detailed definitions of study outcomes and covariates. ^dSmall for gestational age and large for gestational age are respectively defined by the 10th and 90th percentiles from Talge et al using 2009-2010 US natality data. ^eDefined as having a birth record indicating overnight neonatal intensive care unit (NICU) admission in Medicaid claims (defined as a claim with a procedure code of 99468, 99469, 99477, 99478, 99479, or 99480 on the delivery date and on the following day), and nursery level 3 or 4 admission in hospital discharge records. ^fDefined as having any of the following reported on the birth certificate: immediate assisted ventilation, assisted ventilation over 6 hours, abnormal condition indicating seizures, newborn received surfactant replacement therapy, or an abnormal condition indicating antibiotics. ^gThe Centers for Disease Control and Prevention defines severe maternal morbidity as experiencing any of: acute myocardial infarction, aneurysm, acute renal failure, adult respiratory distress syndrome, amniotic fluid embolism, cardiac arrest/ventricular fibrillation, conversion of cardiac rhythm, disseminated intravascular coagulation, eclampsia, heart failure/arrest during surgery or procedure, puerperal cerebrovascular disorders, pulmonary edema/acute heart failure, severe anesthesia complications, sepsis, shock, sickle cell disease with crisis, air and thrombotic embolism, blood products transfusion, hysterectomy, temporary tracheostomy, or ventilation.